This invention relates to an apparatus for adjusting optical characteristics of non-visible radiation such as ultraviolet laser beam which is emitted from a laser beam radiation system, and more specifically, to an optical characteristic adjusting apparatus to be used for correcting a deviation of an optical axis and adjusting a focal distance or the like.
In order to perform an adjustment of a laser beam radiating system which irradiates ultraviolet laser beam, it is necessary that an optical axis and a focal spot of the ultraviolet laser beam are recognized by scanning a screen which is sensitive with the ultraviolet laser beam.
Since there has been no special tool to recognize the above-mentioned characteristics, paper or the like is used, which is mixed with fluorescent material generating visible radiation in response to irradiation or projection of the ultraviolet laser beam. In other words, if the ultraviolet laser beam projects the surface of the paper, visible radiation is effected from the projected portion. The operator may adjust both the laser beam irradiation system and the adjusting apparatus through the observation of the visible radiation by his own eyes.
However, since the visible radiation is generated from only the projected surface of the paper, the-above noted apparatus must be disposed within a space in which the operator can operate the apparatus and can actually watch the irradiated portion on only one side of the paper. This causes a drawback of narrowing the operating space.